Initiation of an antigen specific immune response classically requires activation of T cells via the TCR/CD3 complex and delivery of a second signal e.g. via CD28 of CD40L on T cells. It has been recognized that constant costimulation via CD3 and either CD28 or CD40L results in exponential expansion of T cells in vitro with massive production of TH1 cytokines and CC chemokines. The latter appears to mediate rapid internalization of CCR5, a major co-receptor for HIV and SIV which renders expanded CD4+ T cells refractory to HIV/SIV infection. The aim of this project is to evaluate the capacity of CD3/CD28 expanded T cells collected prior to SIV infection but post influenza/tetanus toxoid immunization to reconstitute immune functions impaired by SIV infection in vivo. FUNDING AMFAR $116,653 1/01/98 - 3/31/99 Naval Medical Research Institute PUBLICATIONS Brice, G.T., Riley, J.L., Villinger, F., Mayne, A., Hillyer, C.D., June, C.H. and Ansari, A.A. Development of an animal for autotransfusion therapy In vitro characterization and analysis of anti-CD3/CD28 expanded cells. AIDS Res Hum Retrovirus 19:210-220, 1998. P51RR00165-38 1/1/1998 - 12/31/1998 Yerkes Regional Primate Research Center